Well-established power distribution systems exist throughout most of the United States, and other countries, which provide power to customers via power lines. With some modification, the infrastructure of the existing power distribution systems can be used to provide data communication in addition to power delivery, thereby forming a power line communication system, which may be a broadband communication system. In other words, existing power lines that already have been run to and through many homes and offices, can be used to carry data signals to and from the homes, buildings, and offices. These data signals are communicated on and off the power lines at various points in the power line communication system, such as, for example, near homes, offices, Internet service providers, and the like.
At the user premises of a subscriber accessing a power line communication system, low voltage power lines are used to carry data communications. Because these same lines may supply power to appliances, equipment and other devices, there may be noise on the power line that attenuates the data signal. In a multi-unit building there are many power lines and devices which potentially may decrease data signal performance. Accordingly, there is a desire to assure an effective power line communication link for a device accessing the power line communication system in a ‘noisy’ environment.
For multi-unit building such as apartment buildings, office buildings, hospitals, mixed use buildings, etc., LV power lines extend to circuit breaker panel(s) or power meters, then may be routed to wall sockets in the various building units. Depending on the design of the building, the LV power lines for one unit (e.g., apartment, room, or office) will often be physically near the LV power lines of one or more other units. When two LV power lines are sufficiently close, the data signal carried on one LV power line may be inadvertently coupled onto the other LV power line. The coupling may occur due to the inherent property of a current-carrying wire producing an electromagnetic (EM) field. The EM field produced by one wire may in turn generate a current in the other wire. As a result, the data signal of one wire may be coupled onto another wire. This electromagnetic coupling occurs when the wires are not sufficiently isolated or sufficiently shielded. Thus, the coupling may occur even though the conductor of the first wire is not physically connected to the conductor of the other wire. One or more embodiments of this invention takes advantage of the coupling described above.
Embodiments of the present invention address some of these needs and offer some advantages over the prior art.